Study the Effect of Liquid Layer Level on the Formation of Zinc Oxide Nanoparticles Synthesized by Liquid-Phase Pulsed Laser Ablation Suha I. Al-Nassar 1,a , Adel. K. Mahmoud 2,b and Furat I. Hussein 3,c 1 Department of Communication, College of Engineering, Diyala University, Iraq 2 Department of Mechanical College of Engineering, Diyala University, Iraq 3 Mechatronics Dept., Al-Khwarizmi College of Engineering, University of Baghdad, Iraq. a suha_alnassar4@yahoo.com, b adel_alkayali@yahoo.com, c furatnejjar@uobaghdad.edu.iq Keywords: Zinc oxide nanoparticles, CTAB solution, Liquid – phase pulsed ablation. Abstract. This work is focused on studying the effect of liquid layer level (height above a target material) on zinc oxide nanoparticles (ZnO and ZnO 2 ) production using liquid-phase pulsed laser ablation (LP-PLA) technique. A plate of Zn metal inside different heights of an aqueous environment of cetyl trimethyl ammonium bromide (CTAB) with molarity (10 -3 M) was irradiated with femtosecond pulses. The effect of liquid layer height on the optical properties and structure of ZnO was studied and characterized through UV-visible absorption test at three peaks at 213 nm, 216 nm and 218 nm for three liquid heights 4, 6 and 8 mm respectively. The obtained results of UV–visible spectra test show a blue shift accompanied with decreasing the liquid level above the target due to the increase in ablation rate and particles production. This blue shift indicates getting a smaller size of nanoparticles and the quantum confinement property of nanoparticles. Also the FTIR transmittance spectra of ZnO 2 nanoparticles prepared in these states show a characteristic ZnO absorption at 435 cm −1 – 445 cm −1 . Introduction The properties and behavior of materials at the nano-scale magnificently vary comparing with same materials at the micro and macro scales. As sizes reduce into the nano-scale, materials show peculiar and interesting changes in their electric, optical, magnetic and chemical properties [1]. Several ways were employed for nanoparticles production, liquid-phase pulsed laser ablation (LP- PLA) can be considered as one of the most important, effective, flexible and efficient techniques used in preparing various types of high purity nanoparticles without surface contamination by residual anions and reducing agents [2]. Compared with others methods LP-PLA has the advantages of procedures simplicity, cost-efficient, easy of controlling the ablation atmosphere and the minimum amount of required chemical species [1,3]. Generating nanoparticles (NP’s) through LP- PLA technique passes through three fundamental phases. Theses phases naturally occurred after focusing a pulsed laser on a target material inside a solvent. Firstly, plasma plume formation due to extreme heating and rapid temperature increasing of the absorbing target material during the laser and material interaction. Secondly, plasma plume expansion leads to quick cooling of the plume region and hence to the formation of nanoparticles clusters. After plasma extinguishing the third phase starts, the generated nanoparticles and clusters encounter and interact with the solvent and surfactant molecules in the surrounding solution [3- 5]. Metal oxide NP’s have many applications in nonlinear optics, optoelectronics, biomedical engineering, electro-optical devices and chemical catalysts [6]. Zinc oxide is promising semiconductor material with unique properties of UV emission, optical transparency, electric conductivity, and piezo-electricity due to a wide band gap (3.37 eV) and large exciting binding energy (60 meV) at room temperature even compared with other semiconducting nanoparticles [2]. This paper is devoted to synthesis of ZnO nanoparticles using PLA of Zn plate in 10 -3 M aqueous solution of CTAB synthesis and study the effect of liquid layer height above target in controlling the size and stability of generated ZnO NP’s in CTAB solution. The produced ZnO NP’s were characterized by FTIR and uv–visible in order to evaluate absorption spectra, particle size and size distribution and overall composite structure [7]. Materials Science Forum Submitted: 2016-07-12 ISSN: 1662-9752, Vol. 880, pp 110-113 Accepted: 2016-07-21 doi:10.4028/www.scientific.net/MSF.880.110 Online: 2016-11-21 © 2017 Trans Tech Publications, Switzerland All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications, www.ttp.net. (#71547189-22/11/16,21:08:37)